soil moisture sensor

1. The product can control the humidity of soil, wide range through the potentiometer to adjust control corresponding threshold, the humidity is lower than the set value, the DO output high level, higher than the set value, the DO output low level;    
2. The comparator USES the LM393 chips, work stability    
3. The working voltage of 3.3 V to 5 V    
4. Equipped with fixed bolt hole, convenient installation    
5. PCB size: 3.2 cm * 1.4 m